Extended MaterialPackageManager main menu.

Example:

    Red Example Score (2013) - materials

        1: magic numbers (Red Example Score)
        2: pitch range inventory (Red Example Score)
        3: tempo inventory (Red Example Score)

        materials - copy (cp)
        materials - new (new)
        materials - remove (rm)
        materials - rename (ren)

    >

The (cp), (rm) and (ren) commands now accompanying the existing (new) command.